This invention relates to vacuum cleaners and more particularly to shop type vacuum cleaners. In still greater particularity, the invention relates to a shop type vacuum having an externally mounted exhaust filter.
Shop type vacuum cleaners typically include a motor operated blower for creating a negative pressure providing for suction of debris into a compartment. The debris sucked into the device is deposited within the compartment and the air is exhausted through an exhaust outlet. Although shop type vacuum cleaners are effective in collecting relatively large and heavier particles, it is not uncommon for some smaller and lighter particles to be contained in the exhaust air. The introduction of such small particles into the atmosphere is environmentally undesirable especially since the shop type vacuums are typically used in closed or not well ventilated locations.
Filters to help filter out these smaller particles which escape containment are known and include both external and internally mounted devices. Internally mounted filters such as that disclosed in U.S. Pat. No. 4,072,483, require at least partial dissembly of the vacuum cleaner to remove, clean or replace the filter element which is not desirable because opening of the compartment disturbs the accumulated debris and allows particles to escape directly into the atmosphere.
On the other hand, external filters such as that disclosed in U.S. Pat. No. 4,613,348, while effective in removing smaller particles that escape containment, are rather large and bulky and are separately located units requiring additional piping or hoses for connection to the vacuum cleaner exhaust.
Accordingly, it is the object of the present invention to provide for a filter device for use with a shop type vacuum cleaner that effectively traps and removes small particles from the exhaust of the vacuum cleaner and which is easily serviced by eliminating the need to disassemble or otherwise expose the debris compartment and which does not require separate hoses and piping.